options: string options are passed by reference

This avoids needless allocations, and we offer for pipes (which need
this because they might be ephemeral) the get_strdup, get_strcpy,
and get_strlen forms. (Those do the copying or allocations while holding
the pipe reference.)

4 files changed, 75 insertions, 21 deletions

diff --git a/src/core/options.c b/src/core/options.c
index 23e63d1c..f3843c0d 100644
--- a/src/core/options.c
+++ b/src/core/options.c
@@ -1,5 +1,5 @@
 //
-// Copyright 2024 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2025 Staysail Systems, Inc. <info@staysail.tech>
 // Copyright 2018 Capitar IT Group BV <info@capitar.com>
 // Copyright 2018 Devolutions <info@devolutions.net>
 //
@@ -9,9 +9,9 @@
 // found online at https://opensource.org/licenses/MIT.
 //
 
-#include "core/defs.h"
-#include "core/nng_impl.h"
+#include "defs.h"
 #include "nng/nng.h"
+#include "nng_impl.h"
 
 #include <stdio.h>
 #include <string.h>
@@ -174,16 +174,12 @@ nni_copyout_sockaddr(
 nng_err
 nni_copyout_str(const char *str, void *dst, size_t *szp, nni_type t)
 {
-	char *s;
 	NNI_ARG_UNUSED(szp);
 	if (t != NNI_TYPE_STRING) {
 		return (NNG_EBADTYPE);
 	}
 
-	if ((s = nni_strdup(str)) == NULL) {
-		return (NNG_ENOMEM);
-	}
-	*(char **) dst = s;
+	*(const char **) dst = str;
 	return (NNG_OK);
 }
 
diff --git a/src/core/stream.c b/src/core/stream.c
index 61a8a3ba..572f28d1 100644
--- a/src/core/stream.c
+++ b/src/core/stream.c
@@ -368,7 +368,7 @@ nng_stream_get_size(nng_stream *s, const char *n, size_t *v)
 }
 
 nng_err
-nng_stream_get_string(nng_stream *s, const char *n, char **v)
+nng_stream_get_string(nng_stream *s, const char *n, const char **v)
 {
 	return (nni_stream_get(s, n, v, NULL, NNI_TYPE_STRING));
 }
@@ -413,7 +413,8 @@ nng_stream_dialer_get_size(nng_stream_dialer *d, const char *n, size_t *v)
 }
 
 nng_err
-nng_stream_dialer_get_string(nng_stream_dialer *d, const char *n, char **v)
+nng_stream_dialer_get_string(
+    nng_stream_dialer *d, const char *n, const char **v)
 {
 	return (nni_stream_dialer_get(d, n, v, NULL, NNI_TYPE_STRING));
 }
@@ -456,7 +457,8 @@ nng_stream_listener_get_size(nng_stream_listener *l, const char *n, size_t *v)
 }
 
 nng_err
-nng_stream_listener_get_string(nng_stream_listener *l, const char *n, char **v)
+nng_stream_listener_get_string(
+    nng_stream_listener *l, const char *n, const char **v)
 {
 	return (nni_stream_listener_get(l, n, v, NULL, NNI_TYPE_STRING));
 }
diff --git a/src/nng.c b/src/nng.c
index 39da87d4..423ddb64 100644
--- a/src/nng.c
+++ b/src/nng.c
@@ -780,7 +780,7 @@ nng_dialer_get_size(nng_dialer id, const char *n, size_t *v)
 }
 
 int
-nng_dialer_get_string(nng_dialer id, const char *n, char **v)
+nng_dialer_get_string(nng_dialer id, const char *n, const char **v)
 {
 	return (dialer_get(id, n, v, NULL, NNI_TYPE_STRING));
 }
@@ -909,7 +909,7 @@ nng_listener_get_size(nng_listener id, const char *n, size_t *v)
 }
 
 int
-nng_listener_get_string(nng_listener id, const char *n, char **v)
+nng_listener_get_string(nng_listener id, const char *n, const char **v)
 {
 	return (listener_get(id, n, v, NULL, NNI_TYPE_STRING));
 }
@@ -1358,12 +1358,72 @@ nng_pipe_get_size(nng_pipe id, const char *n, size_t *v)
 }
 
 nng_err
-nng_pipe_get_string(nng_pipe id, const char *n, char **v)
+nng_pipe_get_string(nng_pipe id, const char *n, const char **v)
 {
 	return (pipe_get(id, n, v, NULL, NNI_TYPE_STRING));
 }
 
 nng_err
+nng_pipe_get_strcpy(nng_pipe p, const char *n, char *buf, size_t len)
+{
+	nng_err     rv;
+	nni_pipe   *pipe;
+	const char *s;
+
+	if ((rv = nni_pipe_find(&pipe, p.id)) != 0) {
+		return (rv);
+	}
+	rv = nni_pipe_getopt(pipe, n, &s, NULL, NNI_TYPE_STRING);
+	if (rv == NNG_OK) {
+		if (nni_strlcpy(buf, s != NULL ? s : "", len) >= len) {
+			rv = NNG_ENOSPC;
+		}
+	}
+	nni_pipe_rele(pipe);
+	return (rv);
+}
+
+nng_err
+nng_pipe_get_strdup(nng_pipe p, const char *n, char **v)
+{
+	nng_err     rv;
+	nni_pipe   *pipe;
+	const char *s;
+
+	if ((rv = nni_pipe_find(&pipe, p.id)) != 0) {
+		return (rv);
+	}
+	rv = nni_pipe_getopt(pipe, n, &s, NULL, NNI_TYPE_STRING);
+	if (rv == NNG_OK) {
+		if (s == NULL) {
+			*v = NULL;
+		} else if ((*v = nni_strdup(s)) == NULL) {
+			rv = NNG_ENOMEM;
+		}
+	}
+	nni_pipe_rele(pipe);
+	return (rv);
+}
+
+nng_err
+nng_pipe_get_strlen(nng_pipe p, const char *n, size_t *len)
+{
+	nng_err     rv;
+	nni_pipe   *pipe;
+	const char *s;
+
+	if ((rv = nni_pipe_find(&pipe, p.id)) != 0) {
+		return (rv);
+	}
+	rv = nni_pipe_getopt(pipe, n, &s, NULL, NNI_TYPE_STRING);
+	if (rv == NNG_OK) {
+		*len = s == NULL ? 0 : strlen(s);
+	}
+	nni_pipe_rele(pipe);
+	return (rv);
+}
+
+nng_err
 nng_pipe_get_ms(nng_pipe id, const char *n, nng_duration *v)
 {
 	return (pipe_get(id, n, v, NULL, NNI_TYPE_DURATION));
diff --git a/src/supplemental/websocket/websocket_test.c b/src/supplemental/websocket/websocket_test.c
index 98bcf658..cb502ef4 100644
--- a/src/supplemental/websocket/websocket_test.c
+++ b/src/supplemental/websocket/websocket_test.c
@@ -13,7 +13,7 @@
 
 #include "sha1.h"
 
-#include <nuts.h>
+#include "../../testing/nuts.h"
 
 void
 test_websocket_wildcard(void)
@@ -138,7 +138,7 @@ test_websocket_conn_props(void)
 	nng_stream          *c2   = NULL;
 	char                 uri[64];
 	bool                 on;
-	char                *str;
+	const char          *str;
 	uint16_t             port;
 	int                  rv;
 
@@ -208,18 +208,14 @@ test_websocket_conn_props(void)
 	NUTS_PASS(
 	    nng_stream_get_string(c1, NNG_OPT_WS_HEADER "NNG-Req", &str));
 	NUTS_MATCH(str, "True");
-	nng_strfree(str);
 
 	NUTS_PASS(
 	    nng_stream_get_string(c2, NNG_OPT_WS_HEADER "NNG-Rep", &str));
 	NUTS_MATCH(str, "True");
-	nng_strfree(str);
 
 	NUTS_PASS(nng_stream_get_string(
 	    c1, NNG_OPT_WS_HEADER "Sec-WebSocket-Version", &str));
-	NUTS_TRUE(str != NULL);
-	NUTS_TRUE(strcmp(str, "13") == 0);
-	nng_strfree(str);
+	NUTS_MATCH(str, "13");
 
 	nng_stream_close(c1);
 	nng_stream_close(c2);